Our work will be concentrated on the oligosaccharides of the alpha-1 glycopeptide and the glycopeptide material which remains on the erythrocyte after trypsin digestion. The former carries all human M and N as well as Vicia graminea specificity while the latter has only the Vicia activity. We will establish the optimal condition for beta-elimination to release maximal amount of the specific oligosaccharide chains and will separate the differing oligosaccharides from M- and N-specific glycopeptides. The homogeneity of the eluted oligosaccharides will be ascertained. Serological activities of the oligosaccharides will be determined by standard procedures as will also their molar composition (GLC, colorimetry). Sugar sequences and linkages will be determined by stepwise enzymatic treatment, by periodate oxidation and by permethylation according to standard procedures. Biosynthesis: We transformed isolated T glycoprotein with CMP-NANA and human serum sialyltransferase into antigen with M or N specificity and isolated NN antigen to MM antigen, depending solely on the MN type of the transferase donors. It is necessary that we carry out the experiments with a large number of sera from persons with MM, MN and NN as well as T and that we isolate the biosynthetic products free of serum components. Medical-immunochemical aspects: We have collected sufficient malignant human tissues to begin the isolation of T-, M- and N-specific structures from them. BIBLIOGRAPHIC REFERENCES: Yang, H.J. and G.F. Springer. Isolation of Human Blood Group M- and N-Active Glycopeptides and Properties of Their Alkali-Labile Carbohydrate Chains. Fed. Proceed. 35: No. 7, p. 1444, 1976. Springer, G.F., P.R. Desai and E.F. Scanlon. Blood Group MN Precursors as Human Breast Carcinoma-Associated Antigens and "Naturally" Occurring Human Cytotoxins Against Them. Cancer 37: 169-176, 1976.